The boundary layer state of powder lubrication indicates the merits and weakness of the lubrication conditions. Powder particles with better lubrication performance and carrying capacity, as well as the good adaptability to extreme conditions, are widely used in many areas. Therefore, the friction and lubrication performance of the powder lubrication interface need studied deeply. With the use of UMT-2 friction and wear tester, the microscopic morphology of boundary layer state of the powder lubrication interface is observed and analyzed combined with shape measurement of laser microscopy. The influence mechanism of load condition (1, 2, 4, 6 MPa), velocity (2, 4, 8, 16 r/min), powder layer thickness (1.5, 3.5, 5.5, 7.5 μm) and surface roughness (0.389，0.745, 1.751, 3.112 μm) on powder lubrication is studied emphatically. The larger contact load is favorable to form a dense boundary layer, improve the lubrication performance. In the low speed, is not conducive to the formation of a complete dense boundary layer, poor lubrication and even produce crawling phenomenon. With the increase of speed, lubrication effect improved, but too much speed will accelerate the powder dissipation. The appropriate amount of powder layer thickness can form a complete thick boundary layer between the frictional interfaces, providing good lubrication ability. The surface with appropriate roughness is favorable for the powder lubricant storage, the formation of the boundary layer and the maintenance of the lubrication action. Reasonable choice of contact load, speed, powder layer thickness and sample surface roughness helps to improve the lubrication performance.